1. Field of the Invention
This invention relates to antioxidants, and more particularly, to new compounds, the method of making them, their use for stabilizing organic material against thermo-oxidative degradation and the organic material stabilized with their aid.
2. Description of the Prior Art
It is known to employ derivatives of sterically hindered phenols as stabilizers for plastics against thermo-oxidative degradation or degradation induced by light. However, many of these compounds do not afford long life protection against these degradative effects, and others exhibit the disadvantage that they discolor the organic polymer in an objectionable manner either when they are incorporaed or under the action of light or on contact with industrial flue gases or even on contact with hot water, greatly limits their applicability in industry. Now new compounds have been found which, surprisingly, are outstandingly suitable for stabilizing organic polymers.
The prior art is represented by such U.S. Pat. Nos. as 3,057,928; 3,210,428; 3,275,597; 3,354,118; and 4,132,702; and Belgium Patent No. 652,510.
3. Related Copending Patent Applications
(a) Ser. No. 062,762 filed Aug. 1, 1979, describes and claims intermediate compounds used in making the compounds of this invention. PA1 (b) Ser. No. 062,763 filed Aug. 1, 1979, describes and claims a method of making the intermediate compounds and the compounds of this invention. PA1 R.sub.2 is alkyl having 1-4 carbon atoms; PA1 R.sub.3 is a straight chain or branched alkylene group having 1-4 carbon atoms; PA1 x is 1-4, PA1 n is 1 or 2, and, PA1 Y is a group of the formulas ##STR5## when n is 1, where R.sub.4 is alkyl having from 12 to 24 carbon atoms, phenyl, or phenyl substituted with hydroxy or alkyl having 1 to 4 carbon atoms, or combinations thereof, or ##STR6## when n is 2, where R.sub.5 is a direct bond, a straight chain or branched alkylene having 1 to 8 carbon atoms, a phenylene group, and, m is 0 to 4.